Quantification of the relative orientation and position of the mandibular condyles.

The human temporomandibular joint (TMJ) is involved in vital functions such as feeding and talking, while its disorder prevalence is reported to be between 5% and 12%. Functional evaluation using quantitative motion analysis tools is interesting in order to better understand normal and abnormal TMJ behavior. But, for the same mandibular displacement, left and right condyles will most certainly give different motion representation: both condyles showing a different shape and volume, being most of the time asymmetric and highly individual. This study performs quantification on relative left and right condyle orientation and position using the spatial location of palpated anatomical landmarks (ALs) and anatomical frames (AFs), on three-dimensional (3D) models created from computerized tomography (CT) performed on 94 mandibles from Université Libre de Bruxelles bone repository, and magnetic resonance imaging (MRI) performed on 11 living subjects. Our aim was to gather as much data as possible on the morphological aspect of the condyle's orientation asymmetry within the same mandible, in order to better address the difference of motion representation that will be observed for the right and left condyles in further kinematic studies.

[Injection of PRP (Platelet-rich plasma) as a treatment for androgenetic alopecia : a systematic review of the literature]. / Injection de PRP (Plasma riche en plaquettes) comme traitement de l'alopécie androgénétique : une revue systématique de la littérature.

INTRODUCTION: Androgenetic alopecia is the most frequent alopecia both in men and women. Despite it affects a large proportion of the population, they are few therapeutic options often restrictive. The injection of PRP in alopecic areas is a new and easy therapeutic option. The aim of this article is to systematically review the literature about this topic by analysing the articles describing the clinical results of this new technique in the treatment of androgenetic alopecia in men and / or women with a follow-up of minimum 6 months. MATERIAL AND METHODS: A systematic review of the PRISMA type from several databases was carried out and identified 7 articles meeting the following inclusion criteria: 1) articles describing the clinical results of the injection of PRP for the treatment of androgenetic alopecia, 2 ) in men and / or women, 3) written in English or French, 4) with clinical follow-up of at least 6 months, and 5) with objective criteria for follow-up of patients and observed complications. These prospective clinical studies are analyzed and compared qualitatively. CONCLUSION: This systematic review of the literature resulted in a qualitative analysis of 7 scientific studies on the effect of PRP injection as a treatment for androgenetic alopecia. Although all the studies concluded in a favorable effect of this new treatment, a larger, rigorous study with objective analysis of the therapeutic effect is necessary.

INTRODUCTION: L'alopécie androgénétique est l'alopécie la plus fréquente que ce soit chez l'homme ou la femme. Bien qu'elle touche une grande partie de la population, les options thérapeutiques sont peu nombreuses et souvent contraignantes. L'injection de PRP dans les zones alopéciques est une nouvelle possibilité de traitement plus simple. Cet article a pour objectif de réaliser une revue systématique sur le sujet en analysant les articles décrivant les résultats cliniques de cette nouvelle technique dans le traitement de l'alopécie androgénétique, chez l'homme et/ou la femme, comprenant un followup de minimum 6 mois. Matériel et méthodes : Une revue systématique de type PRISMA au départ de plusieurs banques de données a été réalisée et a identifié 7 articles remplissant les critères d'inclusion suivants : (1) articles décrivant les résultats cliniques de l'injection de PRP pour le traitement de l'alopécie androgénétique, (2) chez l'homme et/ou la femme, (3) écrits en anglais ou en français, (4) avec un suivi clinique de minimum 6 mois, (5) avec description de critères objectifs pour le suivi des patients et des complications observées. Ces études cliniques prospectives sont analysées et comparées qualitativement. CONCLUSION: Cette revue systématique de la littérature a permis de réaliser une analyse qualitative de 7 études scientifiques sur l'effet de l'injection du PRP comme traitement de l'alopécie androgénétique. Bien que l'ensemble des études analysées soit en faveur d'un effet favorable de ce nouveau traitement, une étude de plus grande ampleur, rigoureuse avec analyse objective de l'effet thérapeutique est nécessaire.

[Use of extraoral implants for nasal rehabilitation with epithesis after carcinologic surgery. A case report]. / Utilisation d'implants extra-oraux dans le cadre d'une réhabilitation nasale par une épithèse après exérèse carcinologique. Présentation d'un cas.

Maxillofacial defect caused by cancer treatment represents a problem affecting the quality of life of patients. Epithethic solutions are indicated if plastic surgery reconstruction is not a valid option for an extensive defect. We present the case of a 42 years-old woman, who had undergone a total nasal resection, for a well-differentiated epidermoid carcinoma of the tip of the nose. The anatomopathologic analysis of the piece of resection showed free margins, and did not reveal any ganglionar metastasis. No radiotherapy was applied. Three months later, four extraoral implants were placed in the frontal and paranasal areas with a transcutaneous approach, in order to avoid crusting resulting from trans-nasal mucosa emergence of the fixtures. After four months, each implant as a bone anchorage was connected with a prosthetic retention device to be connected to the nasal epithese. After four weeks, cutaneous healing allowed the prosthetic steps to be achieved. The use of extraoral fixtures as bone anchorage for a nasal epithesis represents an alternative to more heavy and time-consuming surgical reconstruction techniques. Another advantage is that the site can be monitored easily because the epithesis is removable, as for the carcinologic follow-up. It allows a good retention of the nasal epithesis and an esthetic result which is satisfying for the patient.

[The use of platelet concentrates: platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) in bone reconstruction prior to dental implant surgery]. / L'intérêt de l'utilisation des facteurs plaquettaires de la coagulation: platelet-rich plasma (PRP) et platelet-rich fibrin (PRF) dans la reconstruction osseuse pré-implantaire.

The autologous platelet concentrates--Platelet-Rich Plasma (PRP) and Platelet-Rich Fibrin (PRF)--are used in various medical fields, particularly in oral and maxillofacial surgery. These concentrates contain high levels of growth factors, including the 3 isomers of PDGF (platelet-derived growth factor), 2 of the numerous transforming growth factors (TGF-beta), the insulinlike growth factor (IGF), the epithelial growth factor (EGF) and the vascular endothelial growth factor (VEGF), which are the key elements in wound healing, particularly in bone regeneration. Platelet concentrates are easy to apply in clinical practice and offer potential benefits including rapid wound healing and bone regeneration, and can therefore be considered to be new therapeutic adjuvants. In dental implant surgery they are used in bone reconstruction prior or concomitant to implant procedures, and also for dental extraction socket preservation. Their use result in enhanced bone graft density and maturation. A literature review on the use of PRP/PRF in maxillofacial and dental implant surgery is proposed.

Transverse maxillary stability assisted by a transpalatal device: a retrospective pilot study of 9 cases.

This retrospective pilot study assessed the transverse stability of an original surgical approach in nine patients with moderate transverse maxillary deficiency associated with a sagittal and/or vertical skeletal anomaly. During the one-stage surgical procedure, bi- or three-dimensional anomalies were corrected. Maxillary expansion was guided by a transpalatal bone-anchored device (TPD). Expansion measurements were made 1-2 months before surgery, 6 and at least 12 months after surgery. The transverse occlusion was corrected in all cases. After 12 months the gingival landmarks revealed an expansion range from -0.83 to +2.92 mm for the cuspids, +1.66 to +6.23 mm for the bicuspids and from +2.68 to +4.80 mm for the molars. For the occlusal landmarks, expansion ranged from -2.01 to +3.15 mm (cuspids), from +1.11 to +7.13 mm (bicuspids) and from +2.70 to +6.26 mm (molars). Cuspid expansion was significantly smaller than that of bicuspids and molars. This more posterior expansion was achieved through the surgical procedure. The transverse stability obtained with the aid of the bone-anchored TPD was satisfying. This preliminary study supports the principle of an original surgical approach, called 'Le Fort I--TPD', which combines a Le Fort I osteotomy with a controlled maxillary expansion.

[Interceptive treatments (ages 6-10) of transverse deformities: posterior crossbite]. / Traitements interceptifs (6-10 ans) des dysmorphies transversales: l'articulé croisé postérieur.

By means of a review of the literature, the authors argue the case for early treatment of posterior cross bites. They outline the particularities and advantages of various therapeutic techniques including grinding down the interfering cusps of deciduous canines and palatal expansion in the mixed dentition.

[Maxillary transversal expansion obtained by transpalatal distractor and Le Fort I osteotomy with posterior impaction of the maxilla, in one stage]. / Expansion maxillaire assistée par distracteur tranpalatin et ostéotomie de Le Fort I d'impaction postérieure, en un seul temps.

INTRODUCTION: The transpalatal distractor (TPD", Surgi-Tec, Bruges, Belgium) is a bone support device whose transversal expansion effect is well known in teenagers at the end of their growth and in adults. Surgical assisted rapid palatal expansion is usually carried out before the orthodontic treatment phase. The transversal gain is mainly seen at the anterior level, and can avoid, in some cases, extraction of bicuspids. It is difficult to correct a sizeable posterior transversal deficit using this technique, and patients presenting a complex dismorphosis must go through a second surgical phase to correct the vertical and sagittal abnormalities at the end of the orthodontic preparation. OBSERVATION: We describe a clinical case of posterior transversal surgical expansion, associated with posterior impaction of the maxilla, in one stage, at the end of orthodontic preparation. The osteotomies, the positioning of the distractor and the orthodontic apparatus enable the palatal transversal expansion to be modulated as required. DISCUSSION: The advantages and limitations of this therapeutic technique are discussed.

[Expression of caspase 3 and p53 during physiological apoptosis and apoptosis induced by three teratologic agents during early craniofacial development of the mouse embryo]. / L'expression de la caspase 3 et la protéine p53 au cours de l'apoptose physiologique et induite par 3 agents tératogènes au cours du developpement crânimofacial précoce de l'embryon de souris.

The neural crest-derived mesectoderm gives rise to physiologic apoptosis areas in early vertebrate embryos. Certain teratologic agents increase this phenomenon. The purpose of this work was to detect caspase 3 (which is associated with the apoptosis cascade) and p53 in cell death areas, both during physiological apoptosis and during apoptosis induced by three agents (retinoic acid, methyl-triazene, irradiation). Antibody revelation was performed using the aBC peroxidase kit. Quantifications were also performed on histological sections. We observed caspase 3 uptake on some apoptotic and preapoptotic cells in control embryos, and in the embryos exposed to the three teratogens. Immunoreactivity generally preceded the development of cytological features of apoptosis. However, p53 was expressed only in the embryos exposed to ionizing radiation and methyl-triazene (an alkylating agent), but not significantly in embryos exposed to retinoic acid. The present results throw some light on apoptosis mechanisms in several teratologic conditions.

[Histologic and ultrastructural features of cell death both physiological and induced by two different teratogens in branchial arches of mouse embryo]. / Aspects histologiques et ultrastructuraux de la mort cellulaire programmée et induite par deux agents tératogènes dans les arcs viscéraux de l'embryon de souris.

AIM OF THE STUDY: To observe and compare cell death process both physiological and associated with the administration of two different teratogens (irradiation and retinoic acid) inside cephalic mesectoderm. MATERIAL AND METHODS: Irradiated mice: 2 Gy were administered to E 9 embryos. Retinoic acid: 60 mg/kg were gave to E 8 or E 9 embryos. E 9 - 9.5 and E 10 embryos were removed. E 9 - E 9.5 and E 10 control specimens were collected. We used semi-thin sections and ultra-thin sections observed with transmission electron microscope. RESULTS: The major process is apoptosis, which is increased in experimental embryos compared to control specimens. However, autophagy was observed in retinoic acid-treated embryos, while necrosis can rarely occurs after irradiation. CONCLUSION: If the common process seems to be apoptosis, both teratological models differs owing to their respective secondary features. These differences should be explained by the specific pathogenesis of both teratological agents: ligand-receptor reaction and Hox system disruption in retinoic acid administration, direct aggression against DNA and diffuse cell death process following irradiation. Furthermore, congenital malformations induced by these teratogens are quite different. This can be partially explained by a specific blow of different cellular subpopulations.

[The stomatology and maxillo-facial surgery department]. / Le Service de Stomatologie et de Chirurgie Maxillo-Faciale.

Initially devoted to emergencies, the Department of Oral and Maxillofacial Surgery has grown considerably since 1979. The department now consists of a Maxillofacial Surgery Unit supplemented by several specialised Units in charge of oncology, orthodontics and orthognathic surgery, implantology and all dental specialities. The main themes of research developed in the department include the healing process of oral tissues, the teratogenic effects of various compounds on the cranio-facial region, the study of apoptosis, the role of heat shock proteins, and the management of craniofacial dysmorphosis. These studies have a direct impact on patient management.

[A multidisciplinary approach to orthognathic surgery]. / Approche pluridisciplinaire de la chirurgie orthognathique.

Orthodontists are precisely aware of their therapeutic limits in dealing with maxillofacial dysmorphia. Unstable results and iatrogenic lesions caused by alveolo-dental compensations for displacements of the skeletal base have convinced them of the importance of orthognathic surgery as a complement to their orthodontic treatments. Collaboration between the orthodontist and the maxillofacial surgeon begins as of the moment a displacement of the skeletal bases is established through clinical and cephalometric diagnosis. Due to factors related to their age and dental history, it is necessary to complement the therapeutic provision for adult patients with the provision of a multidisciplinary team. The dentist and the family doctor take part in the decision regarding the treatment to be administered, they provide advice to their patients and treat them according to the chosen therapeutic sequence. Other practitioners are involved, including the physiotherapist or speech therapist, depending on the clinical requirements. This multidisciplinary approach and collaboration are conducive to the quality of the results and patient satisfaction.

[Heat shock proteins, embryogenesis and evolution]. / Protéines de choc thermique, embryogénèse et évolution.

We present results about immunohistochemical identification of several heat shock proteins (HSP'S) during mouse normal and teratological embryogenesis. Apoptotic cells express very specifically and precociously HSP 110. This fact permits to identify apoptotic cells before apparition of morphologic features of apoptosis, but also to quantify the process of cell death in some teratological models, particularly administration of retinoic acid. HSP 86 is expressed in some cell populations, and particularly permanent in germ cells. Our observations brought us to discuss the potential protective role of HSP on germ cells, and the consequence of their inactivation in the macroevolution process, as well as the role of apoptosis in teratology.

[Orthodontic treatment in children and adults]. / L'orthodontie de l'enfant et de l'adulte.

Orthodontics is concerned with the study of dental-maxillofacial development, and the analysis and treatment of anomalies in this development. The orthodontic approach commences with the monitoring of oro-facial functions as of the early stages of childhood (3 to 4 years). This first stage is chiefly preventative. Interceptive orthopaedic treatment is performed, if necessary, on young patients who have reached the mixed dentition stage. This treatment involves the use of fixed or removable braces to correct any irregularity in the maxillofacial development and dental malposition. The treatment for most dental malpositions commences as of the setting in of the secondary dentition (11 to 13 years). The movements of the teeth in the three precise spatial directions are defined with the use of fixed braces. Residual maxillary deformities (prognathism, retrognathism, laterognathism, etc.) are corrected at the end of the growth process or in adulthood through fixed orthodontic treatment combined with maxillofacial osteotomies. Adult patients are treated with the same fixed orthodontic techniques and according to a therapeutic protocol adapted to their specific dental or periodontal mutilations.

Cytochemical identification of HSP110 during early mouse facial development.

Apoptotic cell death constitutes a common phenomenon observed during development. This process plays an important role in the regulation of cell populations and in early differentiation of embryonic organs. Several teratologic situations are considered as resulting in a dramatic increase of the apoptotic process. In mammalian cells, heat shock proteins (HSPs), expressed or increased in response to various stresses, act as molecular chaperones in physiological conditions. In order to determine specific histochemical markers of apoptotic cells in normal craniofacial development, we observed the expression of stress proteins (HSPs) 70, 86, and 110. The apoptotic pattern of mesectodermal cell death areas was confirmed using both nuclear staining (Feulgen) and specific labeling of DNA fragmentation (TUNEL). These areas are localized in the proximal parts of the first and second visceral arches. They are located in mesectodermal and ganglionic cells. Apoptotic mesectodermal populations strongly express HSP110, as shown by the cytochemical identification of HSP110 and by double staining HSP110-TUNEL, suggesting that this protein could be considered as a new marker for apoptotic embryonic cells, and could be used in further teratologic studies to better quantify induced cell death.

Cranio-facial dysmorphism: experimental study in the mouse, clinical applications.

To obtain a better understanding of mandibulo-facial dysostosis and hemicraniofacial microsomia in man, the authors carried out a histologic and scanning electron microscope study of the facial malformations produced in mouse embryos by retinoic acid and methyl-triazene. The administration of 400 mg/kg 13 cis-retinoic acid (RA) to pregnant C57BL mice on day 9 of gestation produced anomalies of the cephalic extremity in the embryos resembling human mandibulo-facial dysostosis. The 64 embryos collected presented hypoplasia of the branchial arches or the snout in 79% of cases, auricular anomalies in 47% and ophthalmic anomalies in 12.5%. Fourteen NMRI mice on day 10.5 of gestation were treated with 1.5 mg (0.5 mg/kg) methyl-triazene (Methyl). The 126 embryos collected had developed a very high percentage of micromandibles and anomalies of both embryonic ears (94.6% to 100%). Finally, although the facial anomalies produced by retinoic acid resemble the human mandibulo-facial dysostosis syndrome, no correlation was found between hemicraniofacial microsomia and the administration of methyl-triazene.

Effects of irradiation and methyl-triazene on craniofacial development in mouse embryos: a semiautomated morphometric analysis.

OBJECTIVE: The purpose of the present study was a 2D-semiautomated morphometric analysis of craniofacial growth in nuclear magnetic resonance imaged (NMRI) mouse embryos. METHODS: The NMRI mouse embryos were exposed in utero to either a single dose of 2 Gy X-irradiation on day 9 of gestation (113 embryos) or to 1.5 mg methyl-triazene administered orally to their pregnant mothers on gestational day 10.5 (124 embryos). An additional group of 108 embryos was used as controls. Digitized pictures of embryos from gestational days 14 to 17 were taken in lateral right view using a video system. Landmarks were located and digitized for computerized analysis of growth changes in relation to developmental stages of the face. RESULTS: The results revealed that the snout of control embryos lengthens during the developmental period considered. The snout of embryos previously submitted to methyl-triazene displayed micrognathia, and all treated fetuses exhibited macroscopic signs of microcephaly with a reduced mandible. The snouts of irradiated embryos appeared shortened at the 14-day stage and continued to shorten as development proceeded. A shortening of the midface was detected macroscopically in 83% of the cases. CONCLUSION: The results of this morphometric analysis enabled us to trace the developmental progression of the induced dysmorphosis and to assess the differences compared with normal development.

[The role of apoptosis during craniofacial development: concepts and importance in pathology]. / Le rôle de l'apoptose durant le développement crânio-facial: concepts et importance en pathologie.

Apoptosis is an essential common final pathway in numerous pathological conditions such as malignant tumors, HIV-related CD4 lymphocytes degeneration, neurodegenerative disorders, and in programmed cell death events during normal embryogenesis. Some teratogenic substances for man and laboratory mammals induce an increase of the apoptotic phenomenon, responsible for the occurrence of some precise cranio-maxillo-facial malformations. The study of cell death during normal or teratogenic embryonic development allows to analyse the cellular mechanisms implied in the control of the apoptotic phenomenon, together with its dysregulation ending in pathological processes. We review the cell death phenomenon during cephalogenesis, both during normal embryogenesis, or in teratogenic conditions known to induce cranio-maxillo-facial malformations.

Effects of irradiation on facial development in mouse embryos.

The purpose of this study was to observe the effects of irradiation on the craniofacial development of NMRI mouse embryos. Two populations of pregnant mice were irradiated with a single dose of 2 Gray on day 8 of gestation for the first population (Po. 1) and on day 9 of gestation for the second population (Po. 2). On gestational days 9 to 17, embryos were submitted to histological and scanning electron microscope examinations. The two populations of embryos presented a high percentage of centro-facial hypoplasia (74.7% for Po. 1 and 75% for Po. 2) which was more pronounced in the latter one. Ocular anomalies were present in 16% of the first population. Cases of anencephaly, cleft palate and anomalies of the central nervous system were found in both populations.

Myxomatous odontogenic tumor of the maxilla. An unusual case with squamous and mucoproducing epithelial component.

A tumor attached to the amelo-cemental junction of a third molar impacted in the maxillary tuberosity, consisted histologically of a myxomatous stroma, in which multicystic cavities lined by a columnar epithelium and mucoproducing cells, together with an aggressive squamous epithelial component were present. Although the diagnosis of polyp of the maxillary sinus cannot be excluded, this lesion most likely constitutes an unusual presentation for an odontogenic myxoma of the maxilla, in which an aggressive squamous epithelial component is present, along with a mucosecreting glandular component.

Noma: clinical and evolutive aspect.

Noma is a gangrenous stomatitis affecting children from developing countries. It may leave dreadful mutilations around the mouth, leading to esthetic disabling sequels and permanent trismus. Iconography of the acute stage and of sequels is presented in this paper, and pathogenesis of the disease is discussed.